Coloring material



Patented Mar. 23, 1937 UNETED STATES COLORING MATERIAL Davidson 0. Wysor, Ridgewood, N. J., assignor to General Chemical Company, New York, N. Y., a corporation of New York No Drawing. Original application June 13, 1931,

Serial No. 544,292. Divided and this application June 21, 1933, Serial No. 676,921

9 Claims.

This application is a division of my co-pending application Serial No. 544,292, filed June 13, 1931, which copending application is a continuation in part of my application Serial No. 339,270,

filed February 11, 1929.

This invention relates to a new coloring material or pigment, to the method of making the same, and to the use of the new material in the production of decorative coatings upon the 10 wall surfaces of buildings and upon building material such as bricks and the like. The invention relates particularly to a novel form of veneered brick or the like employing my new coloring material and to the method of producing such veneered brick.

It has been proposed heretofore to produce decorative coatings upon wall surfaces having a stucco or plaster base and upon building materials such as bricks having a base of clay material by applying to the wall surface or brick various coloring materials or pigments to produce the desired color or shade. The production of so-called veneered bricks composed of ordinary common brick as a base having a coating of coloring material applied to one surface there of is rapidly increasing in importance due to the much lower cost of these veneered bricks as com pared'to the usual face brick of substantially uniform composition throughout. In the production of such decorative coatings it is frequently desired to impart to the'wall surface or to one surface of the brick a rich golden or bronze color which will be substantially unafiected by age and exposure to the weather and particularly for use upon the exterior surfaces of buildings where the ordinary gold or bronze paint rapidly deteriorates and loses its original color, without on the other hand necessitating the employment of expensive gold leaf. Up to the present time no satis- 40 factory and relatively inexpensive coloring material or pigment which will produce a gold or bronze color of a permament nature has been available.

It is the object of my invention to provide a relatively inexpensive coloring material having a rich gold to bronze color or sheen and which is permanent under substantially all conditions of temperature and. exposure to light and the weather. A further object of my invention is the provision of a simple and effective method of producing decorative coatings employing my new coloring material and specifically the production of a novel form of veneered brick employing my new coloring material and which is relatively inexpensive as compared to the ordinary face brick of substantially uniform throughout. r

I have discovered that certain gr: mineral substance mica which are ore saleable as first-class mica because of-t ish, amber or even black cast acquire w or calcined in an oxidizing atmosph golden or bronze color or sheen wh manent and substantially unaffected exposure to the weather. The undesir ish, amber or black color in the re attributed to the presence of substanti of iron occurring as an impurity i mica, and which is present in the fe of oxidation. I have found that by calcining this impure mica at a suflic temperature (about 750 C. for 1 the presence of air or other oxidizing the mica acquires a very pleasing bronze sheen apparently because the f is converted to the ferric state-of oxi: reason of the mineral nature of the substantially unaffected by age and W The calcined mica may be pressel into the outer surface of stucco or p while the stucco or plaster is still plast that the mica particles will become i1 and adhere to the wall surface, whicl be permitted to harden in the usual ifdesired the mica particles may b 1y incorporated with the stucco or p to its application to the wall.

An alternativeand preferred meti ploying this coloring material is in t tion of veneered bricks as previous to. In this manner of practicing m; the raw mica after having been red1 desired particle size, is blown upon 0 slightly imbedded in one or more suri ordinary common brick composed of rial while the brick is still in a pl: i. e., after having been shaped but pr ing been burned or calcined and ha this manner a thin coating or veneer mica is formed upon one surface of The bricks so formed are then calcine in the customary manner, which opera to oxidize the ferrous iron in the n ferric form and thus develop a. rich gol color in the mica. The brick -so prc be employed in the production of w: to provide a permanent rich golden of course at a much lower cost that necessary to uniformly disseminate throughout the clay base of the bricl for example in the manufacture of vely thin facing tiles or blocks, it may le to incorporate the mica. uniformly t the entire mass before shaping or Such operations are of course within of the invention.

various mineralogic forms is included :tice of my invention. The term mica :l to include the several members of ivision as set forth on pages 611 to 663, If Dana's System of Mineralogy, pub- John Wiley & Sons, New York, 1893. rms of mica comprised under three 1 groups of this division are as follows:

proper, including chiefly Muscovite Paragonite Lepidolite Zinnwaldite Biotite Phlogopite' Lepidomelane Serlcite mite or brittle micas, including chiefly Margarite Seybertite Xanthophyllite Chloritoid Ottrelite 'ite, including chiefly Clinochlore Peninite Prochlorite Corundophilite Daphnite Cronstedtite Thuringite Stilpnomelane Strigovite Diabantite Aphrosiderite Delessite Rumpfite iembers of these groups are characteriicaceous structure, that is, they have a feat basal cleavage and split easily into 1e or plates. Of the first group, biotite, phlogopite and sericite are particuidapted to the purposes of the present while chloritoid and clinochlore of the .third groups, respectively, are of such t particularly satisfactory results may obtained. Some micaceous substances .ed in the above grouping have the f exfoliating to a high degree when calcined in the above described manuse of this excessive exfoliation, these are so soft and easily crushed that as continue to disintegrate to such an l are so physically unstable as to be ucible to almost a powder, and hence ed for many purposes for which the z the present invention are well adapte other hand, the micas contemplated accordance with the present invensuch nature that when heated or calvndividual particles of the product are 'ely hard and retain their color and size, and for this reason are well adapted for use on outside surfaces subjected to weathering conditions.

Not all of these micas contain iron as an essential constituent. However, the various forms of mica commonly carry iron as an impurity or accessory constituent or component. My invention therefore includes the use of all forms of mica in which iron is present either as an essential or an accessory component in sufiicient quantity to yield a bronze or golden color when calcined.

I have found as a general rule that the mica should contain not less than about 1.0% iron in order to develop a satisfactory golden to bronze shade upon calcination, although particularly pleasing coloring efiects may be obtained where the iron content of the micas range from about four to about fifteen per cent.

In the appended claims, the term mica is intended to exclude the vermiculites.

I claim:

1. As a new product, mica containing iron in its composition, said iron being in the ferric state of oxidation and suflioient in amount to impart a gold to bronze color to the mica.

2. As a new product, mica containing iron in its composition and which has been calcined at a high temperature in an oxidizing atmosphere to convert the iron to the ferric form, said mica possessing a gold to bronze color.

3. The method of preparing coloring material which comprises heating mica containing iron to a temperature suificiently high but not substantially in excess of that required to develop a golden to bronze color in the mica.

4. The method of preparing coloring material which comprises heating mica containing iron at temperatures of substantially 750 C. to develop a golden to .bronze color in the mica.

5. The method of preparing coloring material having a golden to bronze color which comprises calcining mica containing a substantial amount of iron in its composition in an oxidizing atmosphere at a temperature sufiiciently high but not substantially in excess of that required to develop a golden to bronze color in said mica.

6. The method of preparing coloring material having a golden to bronze color which comprises calcining mica containing not less than about 1.0% iron in its composition at a temperature of substantially 750 C. in an oxidizing atmosphere to develop said golden to bronze color.

7. The method of preparing coloring material which comprises calcining mica containing iron in an oxidizing atmosphere at temperatures of substantially 750 C. for a substantial period of time to develop a golden to bronze color.

8. As a new product, mica containing iron which has been calcined, for a substantial period of time, at a temperature sufiiciently high but not substantially in excess of that required to form colored mica having a gold to bronze color.

9. The method of preparing coloring material which comprises calcining mica containing iron, for a substantial period of time, in an oxidizing atmosphere at a temperature sufficiently high but not substantially in excess of that required to develop a golden to bronze color in the mica.

DAVIDSON C. WYSOR. 

